Conveyor control systems



J. H. DYl-:R ET AL 2,923,420

coNvEYoR CONTROL SYSTEMS 9 Sheets-Sheet 1 Feb. 2, 1960 Filed sept. 2o, 1957 Feb. 2, 1960 J. H. DYER ET AL 2,923,420

' coNvEYoR CONTROL SYSTEMS Filed sept. 2o, 1957 9 sheets-sheet 2 Feb 2, 1960 J. H. DYER ET AL coNvEYoR coNTRoL SYSTEMS 9 Sheets-Sheet 5 Filed Sept. 20, 1957 l T l I/ laas rIllllllI .IMNHWLLET I I I I I l I l l I I I I l l I I I I l L Feb. 2, 1960 J. H. DYER ETAL 2,923,420

v CoNvEYoR CONTROL SYSTEMS Feb. 2, 1960 J. H. DYER ET AL coNvEYoR CONTROL SYSTEMS Feb. 2, 1960 J. H. DYr-:R ET AL 2,923,420

coNvEYoR CONTROL SYSTEMS Filed Sept. 20, 1957 9 Sheets-Sheet 6 7?/ L @m6 GATE pe 6472-' 7/5/ I l I I i l l l I I I I I l 1 l I I I 7 7f2\ 72o f 7/2\ I 7/6 l l I I I 1 l l l I I l l I I I ffOR/VEY Feb. 2, 1960 J. H. DYER ET AL 2,923,420

' coNvEYoR CONTROL SYSTEMS Filed Sept. 20, 1957 9 Sheets-Sheet '7 l i l I l i v |-f1 ($20 dwf/v ff. ova-'e I l l l i l l 5% @7i/uli Feb. 2, 1960 J. H. DYER ET AL 2,923,420

coNvEYoR CONTROL SYSTEMS Filed Sept. 20, 1957 9 Sheets-Sheet 8 I $1 afl-1452 I E' I I L ......J I

United AStates Patent O 2,923,420 coNvEYon CONTROL sYsrEMs John H. Dyer, St. Petersburg, Fla., James R. Horsch, Elmhurst, lll., and Allen E. Smoll, Arlington, Mass., assignors to Stewart-Warner Corporation, Chicago, Ill., a corporation of Virginia Application September 20, 1957, Serial No. 685,338 39 Claims. (cl. 214-11) This invention relates to improved control systems for conveyors. v

It is an object of the present invention to provide an improved control means for semi-automatically routing objects from a conveyor load station to any one of a plurality of conveyor discharge stations, which means Will provide reliable, trouble-free operation with minimum maintenance. c

It is a further object of the invention to provide in control means of the type described above means for monitoring conveyor carriers for detection of malfunctioning control equipment and for providing discharge of objects at 'a predetermined discharge station when their routing is improper due to malfunctioning of the control equipment.

A feature of the present invention is the use of a synchronizing switch which provides` for very accurate control of object transfer functions, flexibility of design in the control equipment and prevention of certain routing faults. Y

Another feature is theuse of a monitor including a photosensitive device for detecting a full or empty condition of conveyor carriers, circuits for vdetermining a proper or improper routing of packages and circuits for causing the discharge of improperly routed packages to a predetermined discharge station.

Another feature is the use of neon tubes in one embodiment to store routing information while objects are in transit on conveyor carriers. i

Another feature is the use of bistable ferrite cores as information storage devices and another embodiment.

Other objects and features will be evident upon a perusal of the following description in which:

Fig. 1 shows a diagrammatic view of a vertical conveyor system of the type in which each routed object is held on a conveyor kload transporting carrier through one or more cycles of the conveyor until the desired dis'- eharge station can accept the object; e

Fig. 2 diagrammatically shows the transfer mechanism which is used to load objects on and unload objects from the conveyor carriers of the system `shown in Fig. 1; y

Fig. 3 shows indetail typical loading control circuits for the system shown in Fig. 1 wherein neon tubes are used to st ore information; e

Figs. 4 and 5, respectively, show in detail"typical Ydischarge control circuits andthe monitorl circuits for the system shown in Fig. l wherein neon tubes are used to store information;

Figs. 6, 7 and 8 show circuits similar to those shown in Figs. 3-5, respectively, using ferrite cores tol store information;

Fig. 9 shows a diagrammatic view of a horizontal conveyor system of the type tin Whichobjects loaded on carriers must be discharged during thevsucceeding. cycle of conveyor operation; ,y e

Fig. 10 shows circuits vfor the loading ycontrol circuits for the system shown in Fig. 9;

Patented Feb. 2, n196() Fig. 11 shows typical discharge control circuits for the system shown in Fig. 9; and

Fig. 12 shows supervisory circuits for the systemshown inFig. 9. y j

The applicant has provided in two embodiments im= proved semi-automatic routing control circuits for anendless vertical conveyor system in which objects Yrouted to a predetermined discharge station are kept on a conveyor carrier until the predetermined discharge station has room to receive the object and does, in fact, remove the object from the carrier even though the object may be held on the carrier during several cycles of theconveyor. For purposes of this application, this will b In general, the recycling system includes a convenf tional conveyor having a plurality of equally spaced carriers thereon. When an object is to be sent from 'a load station to a pre-determined discharge station, an operator at the load station pushes a discharge station selector button corresponding 'to the predetermined dis,- charge station. He then places the object in a tray and in turn places the rtray on a transfer mechanism at 4the load station. j v

Control circuits individual to the load station cause the transfer mechanism to deposit the tray on the next empty carrier passing the load station. The control 'circuits in cooperation with circuits prepared by the selecf tor button transfer a binary permutation code,'assign`e`d to the predetermined discharge station, to a memory drum..

v When the carrier with the object approaches the predetermined discharge station, lcontrol circuits individual to the station detect the assigned code permutations; and; if there is room for the object at the station, the control' circuits will cause a transfer mechanism at the station to remove the object from the carrier. If there is no room for the object at the station, the object will be held on the carrier until room is provided by an operator removing previously received objects from the station.

In the event that malfunctioning of the equipment causes a nonexistent code to be transferred to the memory drum, control circuits at a monitor station cause the unloading of the object 'routed withthe nonexistent code.

In general, the single cycle discharge system is similar except that a monitorstation is not required.

Recycling system-Description of mechanical details More specifically, the recycling system includes a con-v.y

in a clockwise direction about its axis. An yendless chainy 3 supporting equally spaced carriers 4 is operatively fsecured to the wheels 2 and 2G.

In a normal installation t-he conveyor wouldbe Vin stalled in a multifloor building with load stations such` as load station 5 on each floor, discharge stations, su'ch as dischargestation 6 on `each floor and a monitor staf,

tion, such as monitor station 7, in the lowest sub-basement.

" Each load, discharge and'monitor station will have s Amemory drum assembly 12 isprovided forstoring routing information during routing of objects between load anddischarge stations. t The assembly 12 isl loperativelyjconnected to the conveyor 1 through a speed reducer 13 to provide one revolution of the drum 12 for eachcycle of the conveyor.V Appropriate circuits interconnect the station control circuits and the memory drum assembly 12 so that the load station control circuits can transferrouting information to assembly 12 during loading of carriers 4 and sov that discharge control circuits can-detect the routing information in the` assembly 12` t o unload the carriers 4 at the proper discharge stations.

A multilevel synchronizing switch 9 is operatively connected to the conveyor in a manner such that the wipers 1t) engageall contacts of their Yrespect-ive contactsets v11 once during travel of the conveyor a distance equal to thespacing between carriers 4. A wiper 10 and contact set11 are provided for each station. As will be described in detail later, the synchronizing switch 9 provides minutely accurate synchronization between movement ofthe carriers by the load, discharge and monitor stations and operation of the transfer mechanisms into the carriertpath during loading and unloading operations. It permits transfer mechanism operations to be initiated only when carriers 4 are in predetermined positions adjacent the load discharge and monitor vstations ands/only when contact brush sets of drum`12 are in perfect alignment.

A,More specifically, the memory drum assembly 12` comprises a commutator and slip ring section 14, a multi-V channel information storage sectionv 34 and appropriate electrical connections therebetween. The storage section 34 will be described in detail later.

- The commutator and slip-ring section-14 includes a rot'atablyf mounted hollow cylindrical element 15 having contact sets 16, and slip rings 18 and 19. vSection 14 further includesstator brush sets 17 disposed around periphery of element for engagement with the contactsets 16.

Section 14 also lincludes a pair of stator. brushes 48 and 49 disposed for continuous engagement with slip rings 18 aidll; for supplying powerto thememory drum assem- The contacts in each set' 16 are aligned on the outer,

peripheryof element 15 parallel to its axis. The conaeeaeae t tact sets 16 are disposed in radially spaced relationship around the periphery of the elementtlS. The contact sets I6` are equally spaced, andteach contact set'corresponds to a respective one of the conveyor carriers 4.

The stator brush sets 17 are disposed around the periphery of element 15 for engagement with contact sets A stator brush set 17` is provided for each load station, each discharge station andthe monitor station;

and the stator brush sets are positioned in radially spacedl relationship around the element 15 in the same order that their respective load, discharge and monitor stations appear along the cover path. The stator brush sets are preferably spaced apart in proportion to thespacing of their respective load discharge and the conveyor path. l

Aseach of the carriers 4 approaches one of the stations,` its respective contact s et 16 engages the stator brush set 17 4corresponding to the particular station it is monitor stations along t proaching and remains in engagement for a predetermined time `interval thereaften This time interval is determined by the length of the 1contacts and the brushes as well as the rate of relative movement therebetween.` By i making the, time interval during which the contacts and brushes are in engagementenappreciable amount of time--a substantial portion'of the time interval during which the conveyor moves a distance equal to the `spacing between carriers-fandY by using thensynchronizing switch 9 inl a manner 'discussed below, the cost of making the slip ring and commutatorjsectionw14 `isgreatly reduced because extreme accuracy and alignment of contacts and brushes inthe various sets is not necessary.

The synchronizing switch` 9`willtnow` be described in greater detail. As noted above,` a wiper 10 and a corresponding contact'set `11 aireV provided for eachstation.` Each contact set 11 will include as many contacts as are necessary to give the `accuracy of control desired. For example, a typical installation mightkhave a`conveyor with a carrier movement speed of feet perminute, with carriers .spaced 10` feet apart, and with 20 contacts provided in' each" contact set 11. A wiper 10 therefore has twenty contacts it canfengage while a carrier, tadjacent the station corresponding to the wiper, moves 1Q feet along its path. Consequently, the initiation of transfer mechanism movement into its transfer position in the path of an adjacent carrier can bearbitrarilyselected at` ing station control circuit.

In a practical arrangement however, `there are very` short periods of time during whichcontact setst16 and brush sets 17 are not in engagement-ie. asi contact sets 1 6 advance to the next succeedingbrush sets `17. During these time periods, transfer functions cannot be initi ated.Y Therefore, contacts in sets V11 engaged by wipers 10 during `these time periods cannot be used.; t g

Sincetpositionso inches apart can be selected, it can be seenfthatthe initiation of a transfer function canbe' effected within three inches of an arbitrarily selected ver-.t tical position at each station; however, each` arbitrarily selected position must be within a distance equal to the spacing between carriers.`

-Ina typical installation theretis normally a2 second time delay between the initiation of a transfer function `and the `actual positioning of the transfer mechanism in the path of an approaching carrier. t Due to differences inthe operation of various transfervmechanisms,.the transfer insertion` time `may be retarded by as much as 20 percent. Therefore, insertion time mayvary from 2 to 22/5 seconds. i. .1 1 t `In the typical installation described, itwould be pref-' erable vto initiate `atransfer operation when an approach-` of a transfer function and the arrival of the carrier at the t transfer point. This 3 second interval insures positioning of each transfer mechanism in `its transfer position before arrivalof the approaching carrier. t

Thus the commutator and slip ring section 14of the memory drum assembly A12 provides a rough synchroni-` zation between'the conveyor 1 andv thev control equipment, and switch 9 provides a very Vine syncronization 'between the conveyor 1 and the control equipment.

The provision ofthe ,synchronizing switch 9 described above permits Vappreciable flexibility `in Vequipment design.-

a particular installationcannot be changed easily with` respect to synchronizing the engagement of contact sets 16 and statoibrush sets `17. Consequently, without theprovision of synchronizing switch 9 it would not be feas ible to make changes in the arbitrarily selected transfer positions at the various stations. However, by the provision of synchronizing switch 9, the arbitrarily selected transfer positions at each station can be changed merely by connecting a different switch contact, corresponding to the new desired transfer position, to the associatedV control circuit.

A brief description will be. made ofla typical transfer mechanism for' use at each station of the system shown in Fig. 1. The transfer mechanism is shown diagram# matically in Fig. 2. The transfer mechanism 8 includes a housing 201. A platform 202 is secured'in any conventional manner, for example, by a tongue and groove assembly to the upper end of housing 201 for reciprocable movement as shown by the broken line adjacent thereto. The broken line indicates the position that platform 202 would assume when extended into' the path of an approaching carrier to perform a transfer function. The lower edge 203 of platform 202 is transversely grooved. A pinion 204 meshes with the grooved `edge 203 to form a rack and pinion assembly.

The right hand half of platform 202 is conventional in structure, comprising a plurality of spaced parallel bars which pass through a complementary group of spaced parallel bars which form the base of conventional carriers 4. i

, A conventional single phase capacitor starting motor 205 operates the rack and -pinion assembly through a speed reducing device 206. The motor 205 can be operated in either direction by reversing the connection of the input leads 207 and 208 to the A.C. source. When the motor 205 is rotated in one direction, the platform 202 is extended into the path of the conveyor carriers; and, when the motorr2'05 is rotated in the opposite direction, the platform 202 is retracted to its normal position.

An `electrical tray detecting switchv 209 is suitably mounted ,on the housing 201 to detect the presence or absence of a tray 210, a pluralityof which are provided for holding objects to be transported by the conveyor. The switch 209 is shown in its operated position. An actuator element 211 extending through an aperture (not shown) in platform 202 is depressed by tray 210 from a positionslightly above the upper surface of platform 202 to a position coincidentgwith the upper surface of platform 202 to actuate switch 209.

A platform position detecting switch 212 suitably mounted on housing 2.01 is held in operated position by a projection 213 on platform 202 when platform 202 is in its normal retracted position. When platform 202 beginsrto move towardits transfer position in the carrier path, projection 213 disengages switch 212; and switch 212 restores to its normal position. When platform 202 reaches the extended transfer position, projection 213.actuates an extended position limit switch 214.

Although all objects transported by the conveyor will be placed in trays such as 10, the description will merely refer to the objects being transported without mention of.

the trays. The use of uniform trays such as permits the transportation of objects of various sizes and configurations.

As is well known in the art, the transfer mechanisms at discharge stations have associated therewith equipment (not shown) to automatically move objects from the transfer mechanism platform to an adjacent storage rack as soon as the platform retracts to its normal position.

L oad station circuits-Neon tube storage Adetailed description of the control circuits 4forythe control circuit 31 of load station 5, selector 30 of loadlv .y

station 5, and the motor control circuits 300 for the transfer mechanism 8 of load station 5. A set of drum contacts 16 corresponding to the tube group 301 are electrically connectedl to the cathodes of the respective tubes.

It is assumed `that the carrier corresponding to tube group 301 is approaching station 5 and that thek stator brush set 17 corresponding to load station S has just` engaged contact set 16 to connect tube group 301Vv toA control circuit 31. p

For simplicity of description, several relay and switch' contacts have been shown in detached form-a short vertical line intersecting a conductor representative of contacts which are normally open and an X intersecting a conductor indicating normally closed contacts. The detached relay contacts will bear reference numerals corresponding to the reference numerals of their respective relays with the addition of letter subscripts.

The neon tubes in group 301 may be any type commonly used in computer applications, such as General` Electric NE 96 tubes which tire with a plate to cathode vol-tage greater than 130 volts and whichthereafter maintain conduction until the plate to cathode voltage` is somewhat less than 70 volts. vWhen conductingin the circuits shown, the neon tubes will tend to maintain a positive 30 volt potential at their cathodes.

In some instances for ease of description, the phrase writing information in-to a neon tube group will be used to identify the operation comprising the connection of a negative battery firing potential To the cathodes` of certain neon tubes in a tube group to register therein a code permutation characterized by the conducting condition of said certain tubes.

Also the term erase will be used to identify the operation of connecting a positive battery cutoi'potem tial to conducting tubes in a group to cause them'to ceaseconducting. y

Following common practise in the art, the words coder and code permutation will be used in a synonymous sense.

A positive volt supply is connected across stator brushes 302 and 303 (corresponding to brushes 48 and 49, Fig. l)4 and slip rings 304 and 305 (corresponding to` 18 and 19 of Fig. l) to neon tubes 306-1 to 306-7 of group 301 through resistances 307-1 to 307-7 in cathode circuits of tubes 306-1 to 306-7, respectively.- Y i Contacts 308-1 to 30S-7 of set 16 are connected directly to the cathodes of tubes 306-1 to 306-7, -respectively. f

When the carrier corresponding to vneon tube group 301 is empty, all tubes will be nonconducting. When the corresponding carrier is loaded, a predetermined three of the seven tubes group 301 assigned to a predetermined discharge station will be caused to` conduct. Using three out of seven tubes for destination codes provides for a capacity of up to 3.5 dischargestations. It will be understood that the number of tubes used in any denite installation will depend upon thev number of discharge stations used.

A relay 309 is providedin control circuit 31 to detect the full or empty condition of carriers approaching load station 5. As a carrier approaches station 5, corresponding contacts 16 engage brushes 314-1 to 314-7 f corresponding to station 5.

Assuming, as indicated above, that the carrier, corre-j spondng to tube group 301 is approaching stationS, re

'conductors31l andf312', cliodes"313-1toV 313-7, `.stator y brushesT'314-1to 314-7 and contacts 308-1` to 308-7: If noneofthetubes306-1 to 306-7 are conductingdue tofthe carrier being empty,xthe normally energized `relay 309 remains energized overa circuit extending from the positive, terminal of a 100 volt supply-.throughresistance 315, conductor 316, relay 309, diode 310, con-- ductors` 311` and 317 and `resistance 318 to anegative i 100 volt'battery supply. t In this instance with no neonV tube conducting, conductor 311 is slightly above ground potential `becausediode 350 is conducting and thereis only a small potential drop across diode `350. The circuit for-diode` 350 extends from negative battery connection through resistance 318 and diode 350 to ground.

e. However, when-any one of the tubes 306-1 toY 306-7 is conducting, a positive volt potential at its cathode is extended'through the above described relay 309 operating circuit to conductor311. With a positive 30 volt potential at conductor 311,. diode 350 will no longer conduct. Resistance 351 is .of such value relative to resistance 315 as to result in a 30 volt drop across itself.` Consequently, a positive 30 `volt potential appears Yat bothends of relay 309 causing it to restore.

Thus, relay 309tcan detect the loaded or `empty condition 'of an approaching carrier. If theapproaching carrier isxempty, relay 309 remains energized; and, if thecarrieris loaded, `three of its corresponding Vtubes 306-1 to3067` will be conducting to `causerelay `309 to bedeenergized` asdescribed above.` t

The discharge station selectorA 30 includes a manually operable pushbutton, such as 319, for eachY discharge station, including, if desired, one for monitor station 7. Associated with each pushbutton is a relay, such as relay 320, which is energized when the pushbutton is de-v pressed. For example, pushbutton 319 completes a circuit from ground over conductor 321, contacts 322, and conductor 323 and relay 320 tobattery.` t Spring biased contacts 322 will return pushbutton 319 to its `normal position', and relay 320 is held operated over a circuit extending from battery through relay 320, conductor 323, contacts 320d conductor 325, contacts327, conductor` 328,'contacts 329, conductor 330 and contacts 331 to ground. f

. 334, conductor 337',M cgznitacts` 334e,` conductor 338` andY contacts 331.toggrdundls` :Whennrelay334 energizes,` it

closes contacts v334b` tos-prepare av circuitlforenergiz@ ing're1ay339.:lva1f;Yv -i H i y Thus it can be seenthat when one of the push `buttons Contacts 327 and 329 in the holding circuit of relay.,

3201and "all other -'corresponding relays associated with pushbuttons` assigned to diferent'discharge stations provide for restoration of erroneously selected pushbuttons.

For example, assume puslibutton 319 had been selected erroneously instead of pushbutton 319-1.

ton 31,9-1 isdepressed; and contacts 327 will open, to restorerelay 320. AtA the same time relay 320-1 is energized y andheld energized over circuits similar `to those' described for relay 320.

-Relay"320, `when energized, closes contacts 320e, 320I and 320e which prepare a circuit for writingintothe memory drum `assembly 12l coded informationI assigned Before* transfer of the waiting object to a carrier is ntiade,`pu`shbut-V to` the discharge station corresponding to pushbuttonf Arelease relay 332 is provided'in selector` 30 for open-g` ingcontacts 331 inthe holding'circuits of each of the' relays, such"as `relay 320 toA releasesuch relays at the beginning of a transfer operation. i More specifically, ret lay-332is-energized`by contacts 333 which are closed when the transfer mechanism 8 at load station 5 moves from its normal retracted position toward an` extended position in thepathV of an ,approaching carrier. A

Relay 334 in selector 30 is' energized when any one ofthepushbuttons are depressed. ForV example, when pushb'utton 3194 is *depressed relay '334 is energizedfover i:

a "ciriuitf` extending frnm A battery through relay con-t ducto: 'i 335,2 contacts 3361-which "maken before contactssuch-*as v319 is depressed,relay\334 will` prepare a ci'r"` cuit for relayI 339, `and onefofathev relays such as 320 will prepare a circuit for writing a predetermined code' into the information storage sectio`n3`4'. C

VRelay 339 controlsthe initiation `of `a loadingopera" tion. Contacts `340 further `prepare the nenergizing ycir-` cuit of relay 339-when they are closed responsive to `aload' transporting ,..traybeing placed upon the transfert4 mechanism Y8 ofload statiori`5. Contacts `309a`of the` empty carrier detecting relay 309 are closed when relay'` 309 is energized to `further `preparethe'relay 339; i

Thus,l it can betseenzthatltheA operating circuit for ref lay 339 is prepared are fulfilled;

(1)."a tray is p lacedon` transfer" mechanism `8 to close t contacts 340, i A A (2)` thedischarge station ,contacts 334b to close and i v (3) therelay 309` detects the emptycondition an aprmentarily energizing ya synchronizing t, relay` 341.. Relay 341 closes contacts 341a to momentarilyoperate the e relay` 339 ove'r anjobvious circuit. y As indicated above,

the operation of relay 339 will begin ,the sequence ofk operations for `transferring fair object "from `the trans` fer mechanism 8 to the approaching carrier." y

Relay 339 closescontacts 339e to operate tion switch similar to switch 2`14(Fig."'2).` The` motor start relay 342clos'es `contacts `34,21 and `342b `to. starty ai. motor 343 ofthe traiisferi'mechanism. The rmotor 343 moves the `platforrri ofthetransfer mechanism 8 `to its extended position infthepath of vthe approaching carrier. e When the platform reachesA its extended posi-.1 tion, the extendedposition `switch opens contacts 344m` Arestore the motr fstart4 relay 342. Contacts 342a and 342 b will Yopen"t`oistop'the motor 343. The transfer'i mechanism 8 will remain ,in this `position until `the apf` proaching carrier removes the object from its platform.`` WhenV the motor start relay 342 starts themotor 343 in*the manner described"above, it alsoU closes contacts I342e` to applya negative -lOO-volt potential through the code contact set such` as contact seti320a, 320I) and 320c1prepared1by` the operationiof the'discharge sta-,` tion` selector '30 to `av predetermined three of the neona tubes in `group.301. For example, negative battery po-f tential` will be extended through the contacts `345 ofa retracted'position switchtsimilar to switch 212 (Fig. 2),

contacts 342e, 'resistance' 346, 'contacts' 3200, 3'20b,` and 320C, brushes 31'4-1, :S14-2 and 3114-3, contacts 30S-1,'

308-2 and 308-'3to the 'catlicdes ofthe neon tubes 306-1, 306-2 and 306-3. Negative potential at the cathodesof neon'tubes 30-6-1,i 306-2 and 306-3 `will `cause them to conduct. `As indicatedabOVe, once the tubes startto con-` duct,.`they\ivill'` continue to conduct until theirplate to i cathode voltageeiis reduced -to below 70.volts by a shunt* ing circuit. c

Shortly after, tacts 345 will be openedr consequent to` the movement of the platform of the transfer mechanism 8 from its lnorinaliretracted position toward its extended pc'isitiflin:`

for roperation when three conditions`- selector 30 isoperat-edtto cause the motor start relay 342 which locks itself operated over an` ob' vious circuit including contacts, 344 of an extended `posi-j relay closes contacts 342e, the con-.y

. As soon asthe approaching carrier removes the object from the platform of the transfer mechanism 8, a"

tray detecting switch similar to switch 209 (Figi 2) closes contacts 347 in the operating circuit of thel motor the platform of the transfer mechanism 8 previously moved from its normal retracted position toward its extended position, a retracted position switch, similar to switch 212 (Fig. 2) closes contacts 349 in the operating circuit of the motor start relay 348. lConsequently, when removal of the object from the transfer mechanism platform causes closure of contacts 347, as described abo/ve, the motor start relay 348 will be operatedover an obvious circuit.

Relay 348 will close contacts 348a and 348b to ener gize the motor 343. Motor 343 will move the platform of the transfer mechanism 8 to its normal retracted position. In the retracted position of the platform, contacts 349 will open to restore the motor start relay 348. Contacts 348a and 348b will open to stop the motor 343.

The transfer mechanism 8 also includes a switch 360 for preventing double loading of carriers in the event of malfunctioning equipment. The switch 360 may be secured to the platform of the transfer mechanism 8 so that, in the extended position of the platform, it can mechanically detect a full approaching carrier. -If it detects a full carrier, it opens the drive means of the conveyor 1 to stop the conveyor.

Discharge station 6 circuitsneon tube'storage A detailed description of the control circuits for the' typical discharge station 6 will now be made with particular reference to the embodiment utilizing neon tubes for storing routing information. Figure 4 shows in detail the control circuit 32 associated with discharge station 6 and the motor control circuits 401 for the transfer mechanism 8a located at discharge station 6.

- The brush set 17 connected to control circuit 32 en? gages the respective contact sets 16 as their corresponding carriers 4 move adjacent `to discharge station 6. Consequently, when the carrier corresponding to neon tube group 301 is adjacent discharge station 6, the stator brushes 402-1 to 4012-7 of the brush set 17 engage contacts 308-1 to 308-7 (Fig. 3) connected to neon tube group 301.

The control circuit 32 (Fig. 4) will detect a code permutation characterized by neon tubes 30-6-1, 306-2 and more of the neon tubes connected to control circuit 32` by way of brushes y402-1, y402-2 or 402-3 is nonconducting, indicating a nonassigned code ground potential from the cathode of the nonconducting neon' tube will be extended through thev respective diode 405-1, 405-2, orr 405-3 to conductor 406 to cause both sides ofrelay 403l to be grounded, whereby relay 403 remains deenergized.`

However, if all three neon tubes connected to brushes 402-1, 402-2 and 402-3 are conducting, indicating the presence of the assigned code the positive 30-v olt potential at their cathodes will be extended -over the above described circuit to conductor 406 and the codedetect ing relay 403 will operate. v relay 403 extends from ground through conductor 407, relay. 403, conductor 408 and closed contacts'409qof an erase relay 409 to conductor 406 which has a positive 3 -volt potential applied thereto'. v n

.Thus, it` can be seen that, fduringrthe momentaryr operation ntf-the synchronizing relay 404, the ende detent- The operating circuit for asiv i0 inglretay 40s wiiraefenefgizedif itsnssign'e'dnszi i ,A tected and will remain deenergized if a code other than its 4assigned code is detected.

VWhen relay 403 is energized, it closes contacts 403a in" `the operating circuit of a motor-starting relay 410. Af

conventional vacancy limit switch (not shown) controls' normally closed contacts 411 in the operating circuit ofik i the motor-start relay 410. When the discharge station 6 has room to accept oneor more additional objects from the conveyor 1, the vacancy switch maintains contacts?` 411 closed. When the discharge station 6 is full and` cannot receive additional objects from the conveyor 1 unitl a station attendant removes objects therefrom, the` vacancy switch causes contacts 411 to open. f

Consequently, if the discharge station `6 is not full,-A then the energization of relay 403 will cause contacts` 403a to complete the obvious circuit for energizing relay 410 which electrically maintains itself operated over an obviousA circuit, including contacts 412 of an extended position limit switch similar to switch 214 (Fig. 2).

Energization of relay 410 closes contacts 410a and 410b to cause a motor 413` to move the platform (not shown) of transfer mechanism 8a to its extended position'in the path of the approaching carrier. When'plat-v form reaches its extended position, the limitr switch 214 isloperated to open contacts 412 in the holding circuit of relay 410. Relay 410 restores to` stop motor214. Theplatform of the transfer mechanism 8a is now in position to unload an object from the carrier approaching discharge station At5. v

At the same time that relay 403 closes contacts 403a to cause positioning of the transfer mechanism 8a, it also closes contacts y403b to energize the erase relay 409 over an obvious circuit. The contacts 421 in the circuit for relay 409 are normally closed whenever the corresponding storage rack at the discharge station -6 has sufficient space to receive at'least one more object. The contacts 421 open only when the storage rack is full.

Relay 409 closes contacts 409C to extend' positive battery potential from conductor 414 to the cathodes of the three neon tubes connected to brushes 402-1, 402-2 and 402-3 by way o-f diodes 405-1, 405-2, 405-3, respectively. With positive potential applied to their cathodes, the three neon tubes no longer conduct.

The erase relay 409 also opens contacts 40911 which removes negative battery potential from conductor 415.

Prior tothe opening of contacts 409b, the negative battery potential connected to conductor 415 was connected through resistances 416-1 to 416-7 to the cathodes of the seven neon tubes `connected to brushes 402-1 to. 402-7 to prevent neon tubes which are conducting when i first engaged by the brushes from ceasing to conduct. If negative battery potential were not so connected, the positive battery potential connected to the conductor 414 and extended through the resistance network of the control circuit 32 to the cathodes of the four neon tubes coni nected to brushes 402-4 to 402-7 would erase code information stored therein. y

This would cause erasure of code permutations other` than that assigned to discharge station 6.

When the negative battery potential is removed from conductor 41-5 as described above, positive battery potential at `414 is also extended through conductors 417-4,

417-5, 417-6 and 417-7 to the cathodes of the neon tubes connected to brushes 402-4, 402-5, 402-6 and 402-7, respectively, to cause said tubes to cease conducting in the event that one or more was conducting due to. malfunctioning of the control equipment.

With the platform of the transfer mechanism 8a in its `'extended position, as described above, vthe object on the approaching carrier 4 will be deposited on the platform. When the object is so deposited, a tray detecting switch (not shown) similar to -switch 209 of Fig. 2 will close contacts 418 to energize a second motor-startlrelay 419'V over an obvious circuit including contacts 420 Ofi;

i l-platform. positionsensing switch :similarv toxswitchp-zlzf,

The contacts 4,20 are held,619,6111vvh'eir,theV of transfer mechanismSa Vis in its-normal retracted posi` tion,A and contacts 420are1held closed inl all `other posi-VV tions ofrthe platform. Since the platform is in extended position, contacts 420 are closed when contacts -418arev closed asdescribed above., y -When relay 419'is so energized, it'closescontacts 4191: and 4191'Jto operate. motor 413.in an opposite direction to move the'platform to its normal retracted position. With the platform in its normal position, contacts';420 open to restore relay 419. Contacts 419a and241'9biopen to stop the motor-:413. The object on the platform.

moves to an `associated storage rack in a Vmanner-described previously, and the' tray sensing switch opens contacts 418.I 1

i Routing an object from the `loakd station 5 t' discharge'l station 6 neon ntube storageV v "The routing of an object from the load station 5 tothe discharge station 6 will now be described.

The push button 319 ofthe selector 30, which selects( the discharge station 6, is actuated to operate relay 320i and relay334. Relay `320 prepares the code writing cirfor a transfer initiating relay 339.V

*The object is placed upon the transfer` mechanism `8 Fand the traydetecting switch further prepares the circuit;r

for relay 339. When the next empty, carrier, for eX- ample, the carrier corresponding to tube group 301, ap

proaches the load Station 5, relay 309 operates to further:

prepare a` `circuit for relay 339. When the carrier reaches apredeterrnined position, the synchronizing switch 9` operates the synchronizing relay 341 which in turn operates relay 339. l 1

-Relay339 causes the code permutation assigned to the `discharge Vstation 6 to be `written into thel neon 'tubegroupV 301;y Relay 339 also operates the motor start relay 342 which in turn operates the motor 343 to extend the platform ofthe transfer mechanisms into the path of the approaching carrier.

" The approaching carrier removes the object from the.`

platform and the motor start relay 348 is operated to cause the motor 343 to return the platform of the transfer mechanism `8 to its normal retracted position.

The carrier moves along its path ltoward the discharge t properly marked `neon tube groups, i.e. less than three` station 6. Simultaneously, the memory drum assembly 12 rotates 'contacts 30s-1 to 30s-7 0f the neon .mbe

group 301 toward the stator brushes 402-1 to 402-7 associated with the discharge station 6.

t As the carrier approaches the discharge station 6; the contacts 308-1 to 308-7 engage the brushes 402-1 to 402-7. 1

When the carrier reaches a predetermined positionrelative to the discharge station 6, the synchronizing switch 9 operates the synchronizing relay 404 which removes a shunt from the assigned code detectingV relay` 403. The relay 403 operates in response todetecting the assigned code permutation in the tube group 301.

Relay 403 operates the motor start relay 410 which in turn causes the motor 413 to move the platform of the t transfer mechanism 8a into the path of the approaching carrier. Relay 403 also operates the erase lrelay 409. i

which causes the erasure of the assigned code permutation in the neon tube group 301.

When the carrier deposits the object on the platform` of the transfer mechanism 8a, the motor start relay 419 is operated to cause the motor 413 to return the platform to its normal retracted position. `The object then moves4 to an adjacent storage rack.

-Monitor station 7 circuitsl-Neon Tube storage p L A detailed description of the operation of themonitgor-r station `l circuits, Figa 5,Y shows -inY detail the :control c111- r cuit 331 andwthe;motorrcircuits I501 associated with the.k

transfer mechanism 8b of monitor station 7.`

`Thecontrol circuit33 asshown ris `arranged, to detect a'code in passing'neon tube. groups,.such as 301` (Eig. 3),` characterized `by-condu'ction in tubes corresponding'in position to tubes 306-1, 306-2 and 306-4 of tube group: 301;V It ,will be understood however that in differing" installations the monitor station 7 may be assigned several.

codesortnopcode at all.` y Before control circuit`33attempts to detect its assign code, it irst senses the conducting or nonconducting states of the neon 'tubes of each neon `tube group connected thereto-.as its corresponding carrier passesthe discharge* station. 7 to determine whetheror not less than three of' the seven tubes'in` a group being sampled are conducting due to malfunctioning of the control equipment.`

Morelspecically, the monitor station 7 has associated therewith a; conventional photosensitive device, for example, a Clarex CL2,photocell V502 and a sourceyof light` 503 focused on a photocell 502. 2 The light source 503 and vphotocell 502` are positioned suchlthat, when a full carrier passes a predetermined position at .the monitor station 7, the path of the light betweenthe photocellSOZ and the source v503 will be interrupted. The object held on the full carrier is used to interrupt the light rays. 1

The'output of photocell 502 is `fed to the control grid of a conventional amplifier 504.` The amplilierl504 nor?" mally conducts to cause the operation ofa `load detecting relay I505. However; when light from `the source :503-` falls on the photocell 502., the outputof thephotocell drives. the` control grid of the amplifier '504 negative below cutoff. The amplifier no longer conducts and re` lay 505.is restored.' t

' Whenfthe object on 'a loaded carrier interrupts' the lightfrorn source' 503, the output of the photocell is reduced; and the amplifier again `conducts to operate relay 505. Y

-Thus it can be seen that `relay505operates only when a full carrier approaches the monitor station 7.` The load detecting relay505V initiates the detectio'n ofimtubes conducting.

Morespeciically, relay 505 opens contacts 505b to prevent premature erasure of a code stored in a connected neon tube group. 4Relay 505 also closes contacts 505a"t`of` momentarily operate relay 506. Relay 506 closesrcontactsu 50611 to complete a circuit from ground through" conductor 507,1contacts 506a, contacts..508a ofa code erase relay 508,. contacts 509a of a monitor erase relay* ,509 and`voltage divider yresistances 510 and 511 to posi-*' tive battery connected to'conductor 512.` Thus, resist-i` ances V510 and.511` form a voltage dividing network from ground topositive battery` potential whenever` relay 506A closes contacts `50641.

The neontube groups, `such as group 301 (Fig. 3) form" parallel voltagel, dividing networks between ground and, positive.batteyfpotential.` In each neon tube circuit a, groundrpotential will appear at the cathode ofthe neon,I tube` while the tube is nonconducting, and a positive ;.30vo1t4 potential lwill appear at `the cathode if the tube is conductingf `Aseach neon tube group is connected to p the `monitor control circuit `33 of Pig. v5 the cathodesof the tubes areconnectedin circuit with the voltage divider.

network' comprising resistances 510 and 511.

More specifically, the cathode resistances 9307-1 to 307-7 arefconnected in serieswith` resistances 518-1 to 518-7" by way sf eomactssos-i to 3084, brushes 51e-1,l to 516-7 and diodes 517-1 to 517-7. Each cathode ret sistance and itsseriesiconnected corresponding resistance 518`is connected inparallel witharesistance 513 by way t o f conductor 519. Theresistance 513 isconnected across the voltage divider resistance 510 `with ltwo terminals of"l the.resistences` 510 and 513 `connected together at ground` 1.; pctential @ist vithhs @the rwo'tefmnals 561 an@ 15.62

detecting relay 515. r Thus, it can be seen that parallel voltage dividing circuits `are provided by resistances 51,0 and 511 and the,

parallel neon tube circuits; It can further be seen that the diode 514 and the false detecting relay 515 provide a bridge circuit connection between the terminal 561 between resistances 510 and 11 and the terminal 562 which is connected to the cathodes of the neon tubes connected to control circuit 33 by way o'f series resistances 518-1 to 518-7. i p l `The resistances 510, 511, 513, 518-1 to 518-7, and the resistances (similar to resistances 307-1 to 307-7 of Fig. 3) connected inthe cathode circuits of (e'ach neon tubegroup have their relative values adjusted such that the voltage drop across resistance 513 and the circuits paralleled therewith is` greater than thev voltage drop resistance 510 when three or rn'ofre neon tubesy are conducting. With a voltage drop across -513 greater than the voltage drop across resistance 510, relay 51S will be operated. Y

Thus,l it can be seen that if a carrierapproaching the monitor station 7 is full and if a detectable code A(at least 3 conducting tubes) is stored in the neon tube group corresponding to' the approaching carrier, the false code detecting relay 515 will be operated. r i

However, in the event that malfunctioning of the equipment has caused less than three neon tubes in a group to conductthenl the voltag'e drop across resistance 513 will be less than thefvoltage drop across resistance 510-when the Ytube group is connected to brushes 516-1 to 516-7. With the voltage drop across resistance 510 being greater than that across resistance 4513, the blocking diode y514 will prevent current ow and relay 5 15 will not operate.

Assume that a full carrier with its corresponding tube group properly marked approaches the monitor station 7.'

When relay S is operated, in ,the manner described above, it closes contacts 515a. VWith contacts 515a closed, the monitor control circuit 33 is now arranged in a manner similar to the typical discharge control station 32; and, therefore, the monitor control 4circuit 33 is ready toI detect the presence o'r absence of its assigned code in the neon tube group connected therewith,

When the `synchronizingfswitchV 9 energizes the syn-- chronizing relay `520 shortly after the operation of relayl 515, contacts 520a are opened to remove-the shunt from. the code detecting relay 521. The code detecting relay 521 is similar to the code detecting relay 403 (Fig. 3) ofY controlv circuity 32 and functions in a similar manner todetect a code' characterized by the conduction of neon` tubes in the tube group connected thereto, correspondingl in position to tubes' 306-1, 306-2 and 3 06-4 of tubegroup 301. If the tubes correspondingv in position to" tubes 306-1, 306-2 and 306-4 are conducting, the posi tive 30-volt potential at theirhcathodes l:willube extended; by way of brushes 516-1, 516-2 and 516-4 and diodes: 522-1, 522-2, 522-4 and contacts 51`5a` toconductor'523. With a positive '3Q-volt potential at conductor 523, the code` detecting relay 521' will operate over a. circuit extending from ground atconducto'r 507 through contacts 50G-a, contacts 50S-@diode 524 and relay 521 to the positive'30-volt potential at lconductor l523.

In the event that any. one or more of the neon tubesconnected to brushes 516-1, 516-2 and 516-4. is nonconducting, ground potential at itscathode will be' ex.- tended'to conductor 523 to' place a'shu'nt across relay 521?. to prevent its operation. y

When relay 521 operates as described above in re` spensey tothe detection of the assigned code, it closes; contacts 521a in the operating circuit ofthe motor start; relay 525.' If the monitor station 7 `has room to acceptf the object on the approaching carrier, the vacancy limit. switch contacts S26'will be'close'd, and' closure contacts.

521a will operate the motor start relay 525 over an o'bvi-` ou's circuiti.'i The'rriotor start relay 52,5 closes",c'sarfftact 525e' ttiA h'ldit'YS/elf operated fverra tpbvioilscircuit cluding the normally closed' contacts'527 of an extended' position switch similar to switch 214 of Fig. 2. i, i

`Also, relay 525 closes contacts 525]; and 525e` to cause' themotor 528,V to move the platforml of a transfer mechanism 8 'b toits extended position in the path of the approaching carrier. When the platformy reaches Vits ex# tended position; contacts S27/(spento restore relay 525.` Relay 525 opens contacts 525b and 525C to stop the motor 528. Y i i Y l s,

When the assigned code detecting relay 521 operates as described above to operate the motor start relay 525, 4itv also closes'v contacts 521b to` complete an obvious circuit for operating thevrn'onitor erase*relay"5,09.k Relay '509 opens contacts 50V9a'which` causes relay 51S torestore. A s

lRelay`509 further opens contacts 509b to remove negar` tive potential )from the brushes 516-3, 516-5, 516-6 vand S16-7whereby positive potential on conductor 512V is extended `through the resistances S40-3, 0540-5, 5401-6l and S40-7 to the cathodes of the neon tubesI respectively connected thereto to erase any information stored" therein.` i y l n Y i y AAt about the time that relay 509 operates, the motob start relay 52,5, closes contacts 5 25d to operate the code erase relay 508 over anrobvious'circuit. VRelayopjens contacts 508e to restore the assigned code detecting relay, l

52,1. Relay 508 also closes contacts 508b to extend 'positivedbatfte'ry potential from conductor 512 overvcontacts 508b, contacts 520d ofthe synchronous relay 520 which is still operated, conductor 541, diodes 522-1, '522-2 and S22-4to the cathodes of the neon tubes connected therewith to erase the code stored therein. At the Sametime, relay 508 opens contacts=8c to remove negative bat'- teryvkpotentialifrom the .lconductor542 which is normally connected through Iresistances 543-1, 543-2, and 543-4 to brushes 516-1,y 516-2 and 516-4, respectively, totmaintain conductionv of conducting tubesy connected thereto. When the approaching. carrier deposits. its object on. the platform of transfer mechanism 8b, contacts y529 of aitray detecting switch, similar to switch 209 of Fig. 2, will close to operate the motor start .relay V530 over an obvious circuit including closed contacts 531 of a retracted position detecting switch, similar to switch 212 offFfiglZ.I The contacts 531 are normally open `in the retracted position of the,` platform of the transfer mechanisrn 8b, and are closed in all other positions of the' platform t f t .t i

yRelay 530 closes 530e and 530b tocause. the motor 528 to return'the` platform to its retracted position.v When the,pla tform reaches its retracted position, conf tacts 531 open' torestore relay 530. Relay 530 opens contacts530bnand 530C to stop `the motor `5,28. The object deposited on the yplatform of the transfer` mechanism 8b will move in' a manner described previouslyv to' a storage rack, whereupon the tray detecting contacts' S29 will Open. Y. t t

Thus, the false `code detecting relay 515' will operate if threeor more neon tubes connected to brushes 516-1 to 516-7 are conducting, and subsequent thereto the as-lv signed code detecting relay 521 will operate rintheevent of thefdetection of the assigned code to cause the transfer o'f an object from the conveyor 1 to the monitor station 7.

Assume now that a full carrier is approaching the monitor stationt'7mand that its corresponding neon tube' group has an'inadequate code stored thereini.e. less than three neon tubes conducting.

The photosensitive device will operate the full carrier detecting relay 505in the manner described above.V Ref 'lay v505 operates relay 506. false code detecting relay 515' will not operate conse quent to the operation of'relay 506 inasmuch as fewer than three neon tubes in the group corresponding to theV approaching carrier are conducting;

With thefals code" detecting relail S15 Vdeencrgietl` As describedy above, theA andtheloaned. detecting relay 505l energized causing thel of the presence` or absence ofY the codeassignedto ther monitork station 7 Prior to the operationiof thesynchronizing relay 520' the conducting or non-conducting state of the. neon tubes connected to the brushes.516-1,-516-2'and 516-4\is maintained unaffected bythe negative `battery potential connected thereto bylway of resistances 543-1, 543-2 and 543-4 and the positive battery potentialconnected thereto by way of conductor"512, Vresistance 545, conductor 523, ,contacts 520C, conductor 541 and diodes S22-.1, S22-Zand 522-4. However, when the synchronizing relay 520 isoperated by the synchronizing switch 9 shortly after thev operation of relays 505 and 506, it opens contacts "520cm the above describedcircuit Vfor thepositiye battery potential.- The ,negative battery potential is thenappliedthrough the above described branch circuits to the cathodes of the neontubes connected to the assigned code `detecting brushes S16-1,"516-2 and 516-4 to tire the tubes. f i

Thus, in the event that a faulty code is'detected the code'assigned to themonitor` station 7 is-written into the neontube set. i

Relay 520 also opens contacts 520:1 to remove a shunt from the` assigned code detecting relay 521.` Relay 520 also opens contacts 520e to `disconnect the neon tubes connect'edto brushes 516-1, 516-2 and 516-4 from `the circuit for relay 521. Relay 52'1 will-now be operated over acircuitextlending from ground through conductor 507, contacts 5064 and. 508a, diode 524, relay 521,' resistance 545 and conductor 512 to positive battery potential. t

The operation of the assigned code detecting relay 521 initiatesfan unloading operation in a manner similar to that described above with respect to an unloading operation initiated consequent to the detection of the code assignedto the discharge station 7. Therefore, the un loading operation will be described only briey.Y

`Relay4 521 operates the motor start relay 525 in the event that there is roomto accept an additional object at the monitor station 7. Relay 525 operates the motor 528 to` extend the-,platform Yof the transfer mechanism Slaginto vthe path of the approaching carrier. The object relay-530 operates to cause `the motor 528 to return the 516-5, 516-6 and 516-7. Positive battery erase potential at conductor 512 fis extended `to the brushes 516-3, 516-', 516-6 and 516-7 to cut ott conducting neon tubes connected thereto.

`When the motor start relay 525 operates as described immediately above, it opens contacts 508e to remove the negative battery holding potential from brushes 516-1, 5161-2 and 516-4. Relay 525 also closes contacts 508b to extend the positive battery erasing potential from conductor 512 through contacts 508b, contacts 520:1 ofthe operated synchronizing relay 520, conductor 541, diodes 522-1, 522-2 and 522-4 to the cathodes ofthe neon tubes connected to the assigned code sensing brushes 516-1, 5116-2 and 516-4. With positive battery` potential at the cathodes of the neon tubes, conducting ones ofthe' room Vto accept, additional objects at the monitor station 7.

In the eventwthat, whenrelay S21-is operated as desctilicl.alzava` consequent to. i119 dstetioaof the faulty 516 t code, there isino roomto:accept` an additional object? at the monitor station 7, a vacancyglimityswitch `(not shown) willhave previously opened contactsr526 to prevent the operation ofthemotor start relay525.` Thus, an unloading operation cannot be'affectcd. l i

The monitor erase relayv 5091s operated' by contacts 52,1b of the assignedcode detecting relay 521.; `Relay 509` opens contacts 5,0912` to cutoff conducting neon tubesconf nected to brushes516-3, 516-5, 516-61and S16-,Tin the* manner described above.` Relay 5,20 writes the assigned. monitor code -into the tube group as describedabove.` Relay X508 will not be operated inasmuch as the motor startxrtelay,` 525 ,is ,not, operated; :Thus contacts 508b which normally provide erasure of the monitor code re` main open.` Thus, the `-monitor code is written into the` tube group and the carrier `will `keep its load until there is available space atthe monitor station 7. n

When an Aempty carrienapproachesthe monitor,` station t 7, the load detector relay505 will not be operated by a photo sensitivedevice `502. Consequently, neither the` false code detecting relay 515 nor the assigned codezdel tecting relayr 521 can 'be operated` t y i Y When the carrier reaches` a predetermined positionat the monitor station 7, thesynchronizing switch 9 will g operate the synchronizing relay 520.` `The relay 520 opens contacts 520b to remove the negative battery holding` potential from the cathodes ofthe neon tube group corre sponding to the approachingfcarrier. i,

It will be rememberedtthat relay 505 1s `notoperated; and, therefore, contacts 505C'preventthenegativebattery holding potential` from being extended to the cathode `over cathodes of the neon'tubes connected to brushes 516-3,`

516-5, S16-6,5164 in the manner described above to erase any coded information that might be stored in the neon tube due to malfunctioning'ofthe equipment.

Relay 520 also closes `contacts 520d1 to extend the posi-` tive batteryferasepotential ,from4 conductor 512 through contacts 505b of the deenergized load detecting relay` 505, contacts 520b, conductor 541; diodes 522-1, 522-2 and 522-4 and brushes 516-1, `516-2 `and 516-4 to the `cathodes of the neontubes connected to the brushes toerase i Laad station 5 circuits-ferrite core storage A detailed description of the control system" for conl veyor 1 utilizing Vferrite cores for storing routinginformation will now be made. Figs. 6, 7 and 8 show `thecontrol` circuits for the ferrite core embodiment. t -t It will be noted that the same system described above with respect to` neon tube storageis contemplated with regard tomechanical details. It islonly Athe control circuit detail's which'ditfer. I

Thus for the embodiment shown in Figs. 6-8,therewil1` be provided the' diagrammaticallyshown system of Fig. 1.` More particularly, the typical loadgstation` 5 (Fig. 1)

has associated therewith a dischargestatonI selector 30, a control circuit 31 and motor controlacircuitsfor,the

transfer mechanism 8 allshown in `more detail in Fig. `6. t,

Also, the typical discharge station 6 has' associated therewith a` control circuit 32i and motor` controlicircuits `8b all 4shownin ,more detail,y

for the transfer mechanism inltigfgV uw 1, 1,

The monitorstation 7 includes a control circuit 33 partially shown in detail in Fig. 8.

And the transfer mechanism of Fig. 2 is again used for the ferrite core embodiment.

A ferrite core group 601 (Fig. 6) of storage section 34 includes a common winding 602 and a plurality of individual windings 603-1 to 603-6 for the 6 ferrite cores 604-1 to 604-6. One terminal of each of the windings is connected to ground through slip ring 605 and stator brush 606, which correspond respectively to s'lip ring 18 and brush 48 of Fig. l. Only one brush and slip ring are required in this embodiment.

A ferrite core set, such as set 601 is provided for each conveyor carrier 4. Ferrite core 604-1 and each ferrite core corresponding thereto in the other ferrite core sets is used for storing information indicative of the full or empty condition ofthe respective carrier, load monitor cores. Ferrite cores 604-2 to 604-6 as well as corresponding ferrite cores in the other sets are used for storing code permutations assigned to the Various discharge sta-tions, and will be identied as routing code cores. The common winding `602 is used for erasing code permutations subsequent to removal of objects from the carrier corresponding to ferrite core group 601.

Ferrite cores are well known and will be described only briefly. The cores such as core 604-1 are annular rings made of a non-permanent ferromagnetic material which can be circumferentially polarized in either of two directions by passing a current flowing in a predetermined direction through either of two coils. The current is prefably of sufficient strength to saturate the core.

In accordance with conventional usage today, polarization of the core in one direction will be referred to as marking a in the core and polarization of the core in the other direction will be referred to as marking a 1 in the core.

Therefore, a typical identification of the polarized conditions of the cores 604-2 to 604-6 in group 601 will be the 5, channel binary code permutation 01010 indicating that the cores 604-2, 604-4 and 604-6 are polarized in one direction and cores 604-3 and 604-5 are polarized in the opposite direction. A 5 channel code is used by way of example only.

Core 604-1 will be marked "0 if the corresponding carrier is full and will be marked l if the carrier is empty.

The application of a current pulse to contact 615-2 marks a 0 in core 604-1. The application of a current pulse to contact 615-8 marks a 0 in all cores 604-1 to 604-6. The application of a current pulse to the contact 615-1, 615-3, 615-4, 615-5, 615-6 or 615-7 marks a l in core 604-1, 604-2, 604-3, 604-4, 604-5 or 604-6 respectively.

If a l is marked in a core, for example core 604-1, a pulse through winding 602 to mark a 0 in core 604-1 will cause a voltage to be generated in the winding 603-1 of the core 604-1. If the winding 603-1 is connected in a complete circuit, the voltage generated will cause a current pulse in the circuit.

The cores and circuits for all ferrite core sets similar to set 601 are similarly arranged.

The selector 30 (Fig. 6) is similar to selector 30 of Fig. 3, except that each relay such as 320 will close any predetermined number of 5 possible contacts in series with brushes 614-3 to 614-7. Thus any 5 channel code permutation can be selected. With 5 channels available, a maximum of 32 discharge stations can be used.

The transfer mechanism control circuits for the transfer mechanism 8 are similar to those shown in Fig. 3.

The control circuit 31 in this embodiment includes a thyratron blocking oscillator 607 and a multivibrator 608 which operate a relay 609 to initiate a loading operation consequent to the actuation of the selector 30, placement of an object on the transfer mechanism 8 and the detection of an approaching empty carrier.

More specifically, when an object is placed on the platform of the transfer mechanism 8, its tray detecting switch will close contacts 610'in the input circuit to the thyratron blocking oscillator 607. When the selector 30 is actuated to prepare a predetermined code permutation assigned to tne desired discharge station to which the object is to be routed, it closes contacts 611 in the input circuit of the oscillator 607. Contacts 611 are similar to contacts 33411 of Fig. 3, and are operated by a relay similar to relay 334 of Fig. 3.

A synchronizing relay 612 is operated by the synchronizing switch 9 when each carrier reaches a predetermined position at the load station 5. When relay 612 operates, it closes contacts 612a to complete an inputycircuit to blocking oscillator 607 which circuit was prepared as described above by closure of contacts 610 and 611.

Oscillator 607,shown diagrammatically, is a conventional circuit including a 5-element thyratron. The control grid of the thyratron is normally biased negative below cut-0EA to prevent conduction of the thyratronA even while positive voltage is applied to the plate. The plate to cathode voltage is supplied from an A.C. source through a transformer, the secondary of which is connected in the plate circuit of the thyratron. During one-half cycle of the A.C. source, the plate will become positive with respect to the cathode.

When contacts 612A, 611 and 610 are closed, as de-` scribed above,'they apply a positive bias potential to the suppressor grid of the thyratron, and the thyratron will conduct when the A.C. source drives the plate positive with respect to the cathode.

The oscillator 607 also includes a typical RC circuit connected to the thyratron grid. The RC circuit is charged by the plate current of the thyratron when it tires, and it biases the grid sufficiently negative to prevent conduction of the thyratron for a time interval long enough to permit opening of contacts 612a. Contacts 612a remove the positive bias from the suppressor grid. Thus further conduction by the thyratron is prevented.

When the thyratron conducts, as described above, it will send a pulse over conductor 613, brush 614-2, con tact 615-2, conductor 616-2 and winding 602 to ground through slip ring 605 and brush 606.

lf its corresponding ycarrier 4 is empty, the ferrite core- 604-1 is polarized in a direction such as to cause a pulse in the winding 603-1 in response to the pulse through winding 602. If the corresponding carrier is full, the ferrite core 604-1 is polarized such that a pulse through winding 602 will not cause a`pulse in winding 603-1.

Thus it can be seen that when a carrier 4 approaching the loadstation 5 is empty and the oscillator 607 produces an output pulse, a pulse from the winding 603-1 will be extended' to the multivibrator 60S by way of conductor 616-1, contact 615-1, brush 614-1 and con-Y ductor 617. i

The multivibrator 608 is `of any conventional type which can momentarily operate a relay 609 when an in-A put pulse is applied thereto.

Thus, it can be seen that, when` an object is placed on the transfer mechanism 8 at the load station 5 and a se'- lector 30 is actuated to properly route the object, thefrelay 609 will be operated in the manner described above when the next empty carrier approaches station 5.

Relay 609 closes contacts 609a to complete an obvious circuit for operating the motor start relay 618. Relay 618 closes contacts 618a to lock itself operated over `an obvious circuit, including normally closed contacts 619 of an extended position switch of the transfer mechanism 8. The motor start relay 618 closes contacts 618b and r618i: to cause .the motor 620 of the transfer mechanism 8 to advance the platform to its extended position in the path of the approaching carrier. When the platform reaches the extended position, contacts 61'9 of the extended position switch will open to restore relay 461118.

Vmotor 620. t

At the same-timelthat relay 609 operates the motor start relay 618,-it also closes contacts 609b to extend positive battery potential through` the code permutation circuits prepared by the actuated push button of 4selector 30, the stator brushes 614-3 to 614-7 and contacts 61S-3 to 615-7, predetermined ones of the windings 603-2 to -603-6l and slip ring 60S to ground at brush 666 to register in core set 601 a code permutation assigned to a selected discharge station. l

As soon as the empty carrier approaching the load station 5 picks up the object from the platform of the transfer mechanism 8, the tray-sensing switch of the transfer mechanism 8 closes contacts 621 to operatethe motor start -relay 622 over an obvious circuit including contacts 623 of a retracted position switch of the transfer mech` anism 8. The contacts-621 are normally closed when there is no tray on the platform of the transfer mechanism f8 and are opened only when a tray is placed on the platorm.

The contacts 623 are normally open when the platform of the transfer mechanism 8 is in its `normal retracted position. As soon as platform moves a slight distance from its retracted position, the contacts 623 close and remain closed until the platform is again returned to its retracted position. Thus contacts 623 are closed when contacts 621 close as described above.

Relay 622 closes-contacts 622a and 622b to energize the motor 620 in such manner as'to cause the motor 620 to return the platform of the transfer mechanism 8 to its normal-retracted position. In the retracted position of the platform, the retracted position contacts 623 open to restore relay 622. Relay 622 opens contacts 622a and 622b to stop the motor-620.

Discharge station 6 circuits-ferrite care storage A detailed description of the control circuits associated with the typical discharge station 6. Reference is directed to Fig. 7 which shows the control circuit 32, its associated brush set 17 and the motor control circuits for the transfer mechanism 8a.

Briefly, the controlV circuit 32 comprises a ferrite core set 701 and appropriate detecting circuits arranged to detect the code permutation 01010, a blocking oscillator 702 for initiating interrogation lof each ferrite core set similar to 'set 601 of the storage section 34 as its corresponding carrier passes discharge station 6, an oscillator 703 and relay 704 for initiating the operation of the motor control circuits of the transfer mechanism 8a subsequent to theV detection of the assigned code and a second blocking oscillator 705 which operates'the ferrite core set 701.in a manner such that codes, transferred thereto from the ferrite core sets of storage section 34 for detection, are erased in the event that the assigned code is detected and are transferred back to the respective core set in storage section 34 if a code other than that assigned to the discharge station 6 is detected.

More particularly, when a carrier approaches the discharge station 6, its respective ferrite core set ofthe storage section 34 is connected by way of its associated contacts on commutator and slip ring section 14 and the stator brushes 706-1 and 706-3 to706-8 of the brush set 17` to the control circuit 32 of discharge station 6.

For ease of description, it will be assumed that contacts 615-1 and 615-3 to 615-8 of the ferrite core set 601 (Fig. 6)` have engaged brushes 706-1 and 706-3 to 706-8 of the control circuit 32. `The windings 707-1 to 707-6 of ferrite cores 708-1 to 708-6 are connected by way of the-brushesy 706-1 `and 706-3 to 706-7, and contacts 615-1 and `615-3 to 615-7 to the windings 603-'1 to 603-6 respectively of the ferrite core group 601.` l.

Thus, itcan be seenL that, if "the signals'are produced i in any one ofthe windings 603-1 to 603-6, of the-ferrite "20 ingwnding 707,-1v to 707-6 of theiferrite core set 701. signals passing through, windings 707-1 to 707-6 cause corresponding pulses in windings'f709-1 to 709-6 of the ferrite core set 701. Pulsesin'the windings A707-1 to 707-6 polarize the respectiveferrite cores '708-1 to 708-6 t in such manner 'as`to register ls therein.

The operation'of the blocking oscillator the transfer ofcode `permutations from the ferrite core 'set 601 to the ferrite core set 701. The blocking oscil'- lator 702 is identical tothe blockingoscillator 607 described above and will fbe described only briey; If the discharge station has room to accept an object, the contacts 710 will be closed.v When the carrier corresponding tothe ferrite core set 601 reaches a predetermined position relative to a discharge station 6, the synchronizing switch 9 completes an obvious circuitfor operating the synchronizing relay 711;V Relay 711 closes contacts 71111 to place a positive bias on the suppressorV grid of the thyratron of blocking oscillator 702.` When the'pl'ate is driven positive with respect to the cathode during the proper half-cycle of the 'A.C. input to its platev circuit, the thyratron'will lire` momentarily, then cut itself olf in a manner described with respectto `the thyratron of the blocking oscillator 607. 'A pulseA will be'applied to the conductor 712 by the ring of the thyratron-.W

The pulse'from the blocking oscillator 702 is extended over conductor` 712, brush 706-8, contact 615,-8 (Fig; `6) and the winding 602 common tothe ferrite cores in set 601 to ground through slip Vring 60Sand brush 606; :The pulse through common winding602 generatespul'ses in each of the ,windings 603-1to'603-6 inwhich 1`s are registered.` Pulses in windings 603-1V to603-6 cause corresponding pulses `in `windings 707-1 to 707-6 and 709-1 to 709-6 as described above. 1 p

As noted above, a l marked inthe ferrite core 604-1 is representative of an empty condition of its associated carrier. A 0" marked in ferrite core 604-1` is representative of the full condition of its respective carrier 4. A combination of ls and Os marked in ferrite cores 6,04-2 to 604-6 represent a code assignedV to a predetermined discharge station. When the corresponding carrier 4 is empty, ferrite cores `604-2 to 604-,6 will 'have Osregistered therein. t

Windings 709-1,"709-2, 709-3 and `709-6 are `connected to parallel inputs of a conventional OR circuit 712. The winding 709-3 is extended by way of conductor 713 to one input .lead of a.conventional AND circuit 714. The windings 709-5 ismextended by "way of conductor 715 toa second input leadof the AND circuit The OR circuit 712 can be oneof `any number wellknown in the artwhich produces `a` pulse in its output conductor 716 if any one of the windings connected to its `input extend a pulse thereto.` The AND circuit -714 can be anyone of a number well-known in the art which produces a pulse in its `output conductor 717 if signals are simultaneously applied .to e`ach-and ductor connected thereto. Y A complimentor gate 718 is provided forapplying an output pulse to one input lead ofthe AND circuit 714 by way of conductor 719 only in the event thatthe OR circuit 712 does not produce a pulse at conductor `716 when the blocking oscillator 702 produces a pulsev at conductor 712. ,More specifically, :the output lead 716 of the OR circuit 712 is connected to the suppressor grid of a pentode utilized in the complimentor gate 718.` The` output conductor 712 Aof the blockingoscillator-702is connectedrto the control grid of the pentoderofthe4 complimentor gate` 718. The pentode is normally biased be low cutoff, and therefore normally `is nonconducting.`

core set 601 the pulse will be extended to the correspond-` 716, it drives the suppressor.gridksutliciently lnegative to 702 initiates every input con- 2l prevent conduction by the pentode even though the control grid is driven positive by a pulse Lfrom the blocking oscillator 702.

Thus, it can be seen that the complimentor gate 718 will produce a pulse at conductor 719 only if OR circuit 712 does not produce a pulse when the blocking oscillator 702 is fired. p

As noted above, a signal will be produced in winding 709-1 consequent to the operation of the blocking oscillator 702 if the ferrite core 604-1 is marked with a l representative of an empty corresponding carrier. A pulse produced in winding 709-1 will cause the 0R circuit 712 to produce an output pulse at conductor 716 to prevent a complimentor gate 71S from producing a pulse at conductor 719. Similarly, if a pulse is produced in any one of the windings 709-2, 709-4 or 709-6 due to a l being marked in any one of the ferrite cores 604-2, 604-4, or 604-6, the OR circuit 712 will prevent the complimentor gate 718 from producing a pulse at conductor 719.

Thus, the complimentor gate 718 will produce a pulse at 719 only if Ithere is a zero marked in the ferrite core 604-1 indicating a full carrier and zeros marked in the code cores 604-2, 604-4 and 604-6 when blocking oscillator 702 extends a pulse to the common winding 602 of the ferrite core set 601.

The windings 709-3 and 709-5 will produce pulses which will be extended over conductors 713 and 715 to the AND circuit 719 only if the ferrite cores 604-3 and 604-5 have ls marked therein when the blocking oscillator 702 operates to extend a pulse through the common winding 602 of the ferrite core set 601 as described above.

As noted above, the AND circuit 714 will produce an output pulse at conductor 717 only if pulses are simultaneously applied to conductors 713, 715 and 719. Thus, it can be seen that the AND circuit 714 will produce an output pulse at conductor 717 only if the core 604-1 is marked with a Zero representative of a full carrier 4 and the ferrite cores 604-2 to 604-6 have the code permutation 01010 marked therein.

A second complimentor gate 720 similar to the complimentor gate 71S is provided. Conductor 712 is connected to the control grid of the pentode of the complimentor gate 720. The output conductor 717 of the AND circuit 714 is connected to the suppressor grid of the pentode of the complimentor gate 720. The pentode of the complimentor gate 720 normally has its control grid biased negatively beyond cutoi` to prevent conduction in its output conductor 721.

When the blocking oscillator 702 conducts, as described above, it applies a positive potential to the control grid of the pentode of the complimentor gate 720 which would normally cause the pentode to conduct. However, in the event that the AND circuit 714 produces a negative pulse at conductor 717 consequent to the detection of the code permutation 01010 assigned to the discharge station 6, Kthe negative pulse drives the suppressor grid suiciently negative to prevent conduction of the pentode even though the control grid has been driven positive by the blocking oscillator 702.

Thus, it can be seen that a pulse will be produced at conductor 721 in the event that the code permutation assigned to the discharge station 6 is not detected.

Assuming for the moment that the assigned core permutation is not detected, the complimentor gate 720 will produce a pulse at the conductor 721. The output pulse from the complimentor gate 720 is passed through an input storage circuit 722 of the blocking oscillator 705. The blocking oscillator 705 is similar to the blocking oscillator 702 except that the secondary winding of the transformer providing the plate to cathode voltage is opposite in polarity to the secondary winding of the transformer in the blocking oscillator 702. vBy connecting the opposite polarity to the plate circuit of the thyratron 22 of theblocking oscillator 705, the blocking oscillator 705 is capable ofl conduction only during those halfcycles during which the blocking oscillator 702 is not capable of conduction. fire during alternate half cycles.

The input storage circuit 722 includes a conventional time delay circuit so that a pulse at conductor 721 can maintain an input signal on the blocking oscillator 705 until it can re on the next half-cycle after blocking oscillator 702 tires to cause a pulse at the-output conductor 721 of the complimentor gate 720.

When the blocking oscillator 705 fires, it produces a pulse which is extended over the conductor 723 which forms a common single turn winding for the ferrite core set 701. The pulse through the Winding 723 causes any ls marked in the ferrite cores of set 701, to be transferred back to respective ferrite cores in the set 601.

For example, if the carrier corresponding to the ferrite core set 601 was empty, the ferrite cores 604-2 to 604-6 would have been marked 00000 and the ferrite core 604-1.would be marked 1. When blocking oscillator 702 fires, the only signal that will be transferred from ferrite core set 601 to ferrite core set 701 will be from the winding 603-1 to the winding 707-1.

The only signal transferred from ferrite core set 701V to the ferrite core set 601 will be from the winding 707-1 to the winding 603-1 to again mark the ferrite core 604-1 with a l representative of an empty carrier.

Similarly, if the carrier corresponding to ferrite core set 601 is full and a code permutation other than that assigned to the discharge station 6 is marked in set 601, the blocking oscillator 702 will transfer the code permutations in the ferrite core set 601 to the ferrite core set 701. Subsequently, blocking oscillator 705 will tire to transfer code permutations from the ferrite core set 601.

Assume that, when the blocking oscillator 702 fired, the OR circuit 712, the complimentor gate 718 and the AND circuit 714 detected the code permuation 01010 assigned to the discharge station 6 in the manner described above.

As explained above, the AND 714 will produce a negative pulse at conductor 717 to negatively bias the suppressor grid of the pentode of the complimentor gate 720 to prevent a pulse in the output conductor 721 thereof. At the same time, the negative pulse from the AND circuit 714 is extended to the oscillator 703. The oscillator 703 can be any one of the several types well-known in the art for operating the relay 704 in response to a negative input pulse from the AND circuit 714.

rThe relay 704 closes contacts 704a to operate the motor start relay 724. Relay 724 closes contacts 724e to maintain itself operated over an obvious circuit including normally closed contacts 726 of an extended position sensing switch similar to switch 214 (Fig. 2). Relay 724 also closes contacts 724b and 724C to start the motor 725.

The motor 725 extends the platform of a transfer mechanism 8a to its extended position in the path of the approaching carrier. In said extended position of the platform, contacts 726 open to restore the motor start relay 724. Contacts 724b and 724e` open to stop the motor 725.

When the platform of the transfer mechanism 8a moves from its retracted position toward its extended position, a retracted position switch similar to switch 212 (Fig. 2) closes contacts 727 to prepare a circuit for the motor start relay 728. Subsequently, when the approaching carrier deposits its object on the platform of the trans- 'fo'rm mechanism 8a, a tray detecting switch similar to switch 209 (Fig. 2) closes contacts 729 to complete an obvious circuit for-operatingthe motor start relay 720.

Relay 728 closes contacts 728a `and 728b to energize the motor 725. The motor 725 returns the platform of the transfer mechanism 8a to its normal `retracted position. AIn said retracted position, the contacts 727 open Thus, oscillators 702 and 705v 

